Chuck for camshafts and the like



Nov. 30, 1937. w F GROENE CHUCK FOR CAMFSHAFTS AND THE LIKE Filed Oct. 28, .1956 2 Sheets-Sheet l SJW Nov. 3o, 1937. w F GROENE 2,100,955

CHUCK FOR CAMSHAFTS AND THE LIKEv Filed oct. 2s, 193e sheets-sheet 2 m Mmmm Gkas/v Patented Nov. 30,1937

CHUCK FOR CAMSHAFTS AND william F. Groene, cincinnati, ouin, assigner to The R. K. Le Blond Machine Tool Company,l Cincinnati, Ohio, a corporation of Ohio Application october as,

12, claims.

This-invention pertains to a method and chuck for supporting and rotating camshafts whereby turning operations may be simultaneously undertaken on all the journal bearings. Heretofore, two or more different machining operations were necessary to completely turn these journal bear-l ings. This multitude of operations was required because the nature of a camshaft is such that a large number of cutting tools cannot be applied thereto without considerable -distortion and twisting of the workpiece, unless it can be positively held and rotated in such a mannerto permit the application of cutting tools to all the journal bearings simultaneously. Prior to my invention no method or means had been devised to support and rotate a camshaft so as to meet these requirements.

This invention is particularly adapted to machinesA of the Acharacter shown in application Serial No. 121,510 filed January'21, 1937.

'An object of my invention is the provision of a novel method of preparing and chucking an un'nished camshaft intermediate its ends whereby it maybe positively centered and rotated.

Another 'object is the preparation of a portion of an unfinished camshaft whereby it may be accurately` chucked -intermediate its ends so as to expose all of the journal bearings for simultaneous turning. A

Anotherobject is to provide on an unfinished camshaft a finished cylindrical surface and a driving lug associated therewith whereby said camshaft may be accurately centered and positively driven intermediate its ends.

Further'objects will appear in the course of thefollowing description of the drawings in whichz- Figure I is an end view of a center drive chuck, utilizing the principles of my invention, showing a camshaft held in working position.

Figure II is a section on line II-II of Figure I particularly showing the centering and driving members engaging a camshaft and the clamping cam for actuating the clamping jaws.

Figure III illustratesl atypical Vcamshaft for an internal combustion engine showing Darticuflarly the finished cylindrical portion anddriving lug.

Figure IV is a transverse sectionon line IV--IV of Figure III showing the driving lug adjacent a cam lobe. A

Figure V is an axialview of the clamping cam. Figure vVI is a side view of the clamping, cam to clearly show the tapered cam portions.

` Figure VII is an end view, partly in section on isssjfserial No. '108,039

(ci. sz-i) line V'lI-VII of Figure" II, showing the clamping cam rotated to force the arcuate clamping jaws into contact with the work piece.

Briefly in the practice of my invention, I provide a chucking device having a xed member adaptedto receive and support a finished cylindrical portion of a work piece for centering said work piece; a fixed member adapted to engage a vdriving lug on the work piece for rotating said work piece; and suitable clamping means to hold the cylindrical portion in engagement with said supporting member. i

In the practice of my invention I also'provide in a chuck clamping means comprising a pair of arcuate jaws and cam means for actuating said jaws,the cam means being-rotatable for moving the jaws to and from a work piece in the chuck and movable axially for adjusting the cam means so as to move the jaws in predetermined relation ,to said work piece.

combustion engine camshaft comprising the main shaft portion I, the journal bearings- 2, 3, I, and 5, the cam lobes 6, an eccentric 1 for" fuel lpump actuation, concentric portions 8, for steady rest purposes in machining the shaft, and the distributor drive gear. portion 9. In order to prepare the camshaft in carrying out my invention I propose to premachine a concentric cylindrical portion on the shaft as for example the portion 9 and also to provide a driving lug I0 formed integral with the shaft at -the time of forgingor casting the camshaft. In the particular example of Figure III, I have shown the lug I 0 formed adjacent one of the cam lobes 6. The purpose of this is to give, added rigidity and strength to the lug which it must have to withstand the cutting strains imposed on it when tools are simultaneously operating on the journal bearings 2, 3, I, and 5. The lug I0 is also arranged on the camshaft in close proximity to the machined portion 9.

The combination of the machined portion 9 and the lug I 0 constitutes oneposition of engagement for chucking and driving the camshaft. It is also fully within the scope of my invention to provide a plurality of such positions for chucking. For example the portions 8 might be premachined and appropriate lugs provided.

adjacent these portions so that the camshaft might be chucked and driven at a plurality of points along the shaft, a very desirable arrangement when .working upon `extremely long -iamshafts with large numbers of journal bearings t9 be machined. Also, by utilizing chucking deshafts may be centered and axially-aligned in the 7 vices at two or more points on the camshaft said machine without the us of any centering means/ 1n the ends of the shaft, this feature being/ptrticularly valuable when it is desirable simulta-- neously to machine the ends II and/I2 of the shaft.

is usual for center drive chucks.

The bearing I4 is retained on the ring gear I3 by suitable retaining plate I9 held to the ring gear by screws 28. The bearing I5 is retained on the ring gear I3 by the retaining plate 2I held to the ring gear I3Y by screws 22.

The ring gear I3 has a straight bore 23 and a connecting tapered bore 24; the plate 2I likewise has a straight bore 25 and a connecting tapered bore 26. In a suitable recess 21 in the ring vgear and the plate 2|, is fixed the centering and locating member 28 to the surface 29 of the ring gear I3-by means of suitable screws 38. The member 28 has an arcuate bearing portion 3I facing 'toward the axis of the chuck and adapted to receive and center the portion 9 of the camshaft.

The driving member 32 is secured to the member 28 by suitable. scr'ews 33 and has a slot 34 facing toward the axis o1' the chuck. The slot engages the lug I8 of the camshaft so as to cause the camshaft positively to be rotated upon rotation of the ring gear I3.

Suitable clamping means is provided for holding the portion 9 in contact with .the bearing 11,36 slidable in suitable arcuate guideways 31 and 38 formed in the ring gear I3, the jaws being held in said guideways by the plate 2|.

Resilient means arepreferably provided for normally urging the jaws away from ,contact with the work piece. A convenient arrangement comprises engaging gear teeth 4I cut on the periphery of the jaws 35 and 36. The plungers 39 are urged upwardly (Fig. I) by means of the springs 42, the plungers and springs being carried in suitable guideways 43 formed in the ring gear I3 and conned therein by the plate 2I. The work engaging ends 44 and 45 of the jaws 35 and 36 are formed as concave surfaces nicely fihttifng theperiphery of the .portion 9of the cams a t. y f

The means for controlling the movement of the jaws 35 and.36 to and from the work piece is the rotatable clamping cam 46. This cam has a bearing portion 41 journaled in the bushing 48, and a bearing portion 49 journaled in the bushing 66 xed in the ring gear I3. The bushing `48 is mounted in'theJ threaded bore 5I in the plate 2l and is provided with splines 52 at its outer end whereby it may berotated by a suitable spanner wrench for axial adjustment in the bore, 6I. A locking means for holdingthe bush-` ing 48 in adjusted position comprises the ring 53 having a splined bore 54 fitting over the splines 52 of the bushing 48 and secured to the plate 2I by screws 55.

Tire/'clamping cam element 46 has a anged ,portan 5s adjacent the hearing portion n which abuts against the inner face of the bushing '48 to limit the axial movement of the cam 46 away from the clamping jaws 35 and 36. Intermediate the flanged portion 56 and the bearing portion 49 is the tapered actuating cam portion 51 having convex cam surfaces 58, on -the opposite end limits thereof. These cam surfaces 58 are angularly related to the axis of rotation of the clamping cam member 46 and engageangularly related surfaces 59 formed on the outer ends of the clamping-jaws 35 and 36, as seen in Figs. I, II, and VII, when the cam member 46 is rotated to unclamped position, Figures V and VII, the surfaces 68 of the outer ends of the jaws 35 andv 36 bear against the faces' 6I of the portion 51v to arrest further outward movement of the jaws 35 and 36 under the influence of the springs 42. A suitable socket 62 for a wrench provides means for manually rotating the clamping cam 46.l

It can be clearly seen that the tapered construction of the surfaces 58 and 59 will cause the clamping cam 46 to be urged axially away from the clamping jaws 35 and 36 so as to cause the vface 56 to abut against the bushing 48, and also Having fully described my invention, what I claim and desire to secure by Letters Patent is:

1. A process of treating unmachined camshafts having a main shaft portion, journal bearings, and cam lobes for simultaneously finishing a plu'- rality of said journal bearings in a single chucking operation, which comprisesforming -a driving lug on said shaft and machining a cylindrical portion on said shaft concentric with its axis of,

rotation, and chucking said work in a. chucking device, said work piece being centered by engagement of said cylindrical portion with a work locating abutment on said chuck fixed with re'- spect to the centerof rotation of said chuck and the clamping of said portion thereagainst, said work piece being rotated by said chucking device by engagement of said driving'lug with a driving abutment fixed on said chuck.

2. A process of treating unmachined camshafts having a. main shaft portion, journal bearings, and cam lobes for'simultaneousiy finishing a D111- rality of said journal bearings in a single chuckingoperation, which comprises'forming axially spaced driving lugs on'said shaft and machining axially spaced cylindrical portions on said shaft concentric with its axis of rotation, chucking said work in a plurality of chucking` devices, simultaneously finishing a, plurality of said journal bearings, in said chucking operation, said work piece being centered solely by engagement of said Gylindrical portions with work locating abutments on said chucks nxed with respect to the center of rotation of said chuck and the clamping of said portions thereagainst, said work piece being rotated by said chucking devices by engagement of said driving lugs with driving abutments xed on said chucks.

'3. The method of chucking a camshaft for machining the journal bearings thereof, which comprising finishing a cylindrical area on the prepared in a suitable chucking device by defiprepared in a center drive chucking device by definitely located abutment means of the device presenting abutment areas to said cylindrical area and said lug, said cylindrical area serving to center said shaft, and said lug serving to rotate said shaft upon rotation of said chucking device.

5. In a center drive chuck, means presenting surfaces equidistant from the chuck axis at one side thereof to receive a cylindrical part of a work piece andA hold it coaxial with the chuck, said chuck having arcuate guides at opposite sides of said means, arcuate jaws guided in said guides, each adapted to present an end to an area of the cylindrical part of the work, which areas are spaced apart along a line beyond the axis of the Vchuck from said first mentioned surfaces, a

clamping cam acting against the opposite ends of both of said jaws to force them against said work, said clamping cam comprising a rotatable element having peripheral cam portions diametrically opposite each other, each of said portions being adapted to engage an end of a jaw, and means on said chuck to engage' another part of the work to cause the work piece to rotate with the chuck.

6. A center drive chuck as set forth in claim wherein the cam portions are angularly disposed relative to each other and to the axis of rotation of said rotatable element.-

7. In a center drive chuck having an axial bore, work surface engaging centering means located in said bore, arcuately guided clamping' means to enguage the surface beyond the center from the centering means, and means to straddle another part of the work adjacent said centering means, said straddling means being adapted positively to drive a work piece in the chuck.

8. In a center drive chuck, means for accurately centering and positively driving a work piece, arcuate guides at opposite sides of-said means, arcuate jaws guided in said guides each presentsaid centering means.

ing an end to a part of the work piece, a clamping cam comprising a rotatable element, having peripheral cam portions formed thereon {substantially diametrically opposite each other, acting against the opposite ends of both jaws to force them against the workpiece, and resilient means acting to withdraw said jaws from the work as the jaws are relieved of the action of said clamping cam.

9. In a center drive chuck, means for accuratevly centering and positively driving a work piece,

arcuate guides at opposite sides of said means, arcuate jaws guided in said' guides, each to present an end to a part of the work piece, a clamping cam comprising a rotatable element, having peripheral cam portions formed thereon substantially diametrically opposite each other and angularly related to the axis of rotation of said rotatable element, said cam portions acting against the opposite ends of both jaws to force them against the work piece, and means for axially adjusting said rotatable element relativeto said jaws.

10. In a chucking device for camshaft, means to engage the premachined periphery of the distributor drive gear portion of the camshaft so as to center the shaft in the chuck, abutment means to engage a driving abutment means on the shaft so as positively to rotate the shaft with the chuck, and clamping means engaging said distributor drive gear portion to hold said shaft engaged with camshaft, means to engage premachined cylindrical areas on the main shaft portion of the camshaft so as to center the shaft in the chuck, abutment means to engage driving abutment means on the shaft so as to positively rotate the shaft with the chuck, and clamping means engaging said cylindrical areas to hold said shaft engaged with said centering means, said driving abutment means constituting 1 1. In a chucking device fuif a projecting integral driving lug formed on the shaft adjacent to said premachined cylindrical areas.

12. In a center drive chuck, means to engage axially spaced premachined cylindrical areas on a work piece so as to center and axially align the work piece in the chuck, abutment means to engage driving abutment means on said work piece so as to positively vrotate the work piece with the chuck, and clamping means engaging said cylindrical areas to hold said work piece engaged with said centering means.

WILLIAM F. GROENE. 

